1. Field of the Invention
The present invention relates generally to elimination or minimization of a liquid blowdown stream from an incinerator system which employs wet flue gas scrubbing equipment, and more particularly, but not by way of limitation, to an incinerator system wherein a flue gas slipstream is employed to evaporate water from a scrubber blowdown stream.
2. Discussion
An incinerator may produce a hot flue gas stream containing particles and toxic metals such as cadmium and mercury which must be removed before the gas can be released to the atmosphere. The hot flue gas stream can also contain sulfur, chlorine and other compounds which are acidic and which also must be removed prior to release of the hot flue gas stream.
The use of a baghouse to remove particulate matter from a hot flue gas stream requires many special features to ensure successful and long term operations. Many of the salts and particles encountered are corrosive, the particles are small in size, and most systems are installed outside. As a result, special coatings, special bags, and extensive insulating and electrical heating devices are often required.
The use of wet scrubbing equipment to remove undesirable gaseous and particulate matter from incinerator flue gas results in a liquid blowdown stream requiring disposal. The liquid blowdown stream typically contains 3% to 15% soluble salt and ash removed from the flue gas. Water treatment facilities, in many cases, are limited in the amount of dissolved salts and suspended solids that can be processed. Deep wells are being closed, thus alternate methods must be found to treat or minimize the blowdown stream from incinerators.
The present invention provides an improved system for eliminating or minimizing liquid blowdown which solves the above mentioned disposal problems related to the liquid blowdown stream, with additional advantages which are described herein for reducing the costs of producing a dry waste with its significantly lower disposal costs.